The question is stated so vaguely as to be meaningless. "Usefulness"- for whom? Where would Kofi Onan be if not for UN? For him it is useful. Ditto for all the diplomatic spies employed there and for tinpot dictators occasionally visiting the place to strike a pose, squeak a little, and do some shopping...
Ditto for all the diplomatic spies employed there and for tinpot dictators occasionally visiting the place to strike a pose, squeak a little, and do some shopping
Right on money. If they want to have a debating place and one convenient hub for diplomats to save on travel, let them do it in a quiet place like Iceland, for example. I don't see them agree to relocate into the middle of Africa or South America, but Iceland: well developed to be an effective host, but far from distractions of NYC type.
I think US would be well served even to pick a tab for relocating them there (or anywhere). Just to get rid of them, would be my pleasure.